The present invention relates generally to thermally cured sealing and/or adhesive materials, and more particularly to improved methods and apparatus for curing such materials with the aid of an electrically heated conductive element or heater trace.
In the manufacture of various devices and components there is often a need to adhere one object to another object and/or seal a surface of one object to a surface of another object. Various adhesives, glues and other sealants are available that may be used for this purpose. One exemplary group of such xe2x80x9csealing materialsxe2x80x9d includes materials that are cured or otherwise activated, etc., using thermal energy (i.e., heat).
During the manufacture of certain ink jet print cartridges, for example, a flexible strip that includes various electrical contacts and electrical traces is adhered to a pen body using a cover layer adhesive. While the cover layer adhesive adequately holds the flexible strip and pen body together, there is an additional need to form a seal around all or part of the flexible strip to prevent certain liquids (such as corrosive ink) from coming in contact with the electrical traces/contacts. This seal, for example, can be formed using a thermally cured sealing material. Here, it should be understood that the sealing material can be a sealant, adhesive, or other type of material that can adequately provide a seal around all or part of the flexible strip.
In this print cartridge example, the sealing material is configured to prevent liquids such as inks, solvents, etc., associated with the operation and/or maintenance of the printing device and print cartridge, from seeping through and entering the cover layer adhesive region and electrically shorting or otherwise deleteriously affecting (e.g., corroding) the electrical traces/contacts provided on the flexible strip. As such, the sealing material needs to be selected such that it is substantially impermeable to such liquids and is able to withstand the operating parameters of the printing device/environment. The sealing material should also be selected such that it does not interfere with the operation of the print cartridge during printing operations. For example, in certain implementations, the sealing material may need to exhibit a significantly low physical profile to allow for the print cartridge to be operatively placed in close proximity to a print medium within the printing device. The selection of the sealing material may also be based on the needs of the manufacturing process. For example, to provide an efficient manufacturing process it may be beneficial to select a sealing material that can be quickly applied, cured and/or dried.
Based on these needs and/or others, thermally cured sealing materials appear to provide a satisfactory solution. Unfortunately, when conventional heating techniques such as, e.g., forced heated air, are employed to thermally cure the sealing material the resulting seal between the flexible strip and pen body may have small openings that allow inks and other liquids to penetrate though the seal. In certain instances, for example, it has been found that air that is trapped between the flexible strip and pen body during the application of the sealing material can expand during the subsequent thermal curing process and form bubbles or holes that breach the resulting seal.
Consequently, there is a need for improved methods and apparatus for thermally curing sealing materials.
Methods and apparatus are provided for forming a seal between two or more components using a thermally cured sealing material. One exemplary method includes selectively applying an electrical signal to a heating trace on a first component, applying a sealing material between at least a portion of the first component and at least a portion of a second component, and at least partially thermally curing the sealing material using thermal energy generated by the application of the electrical signal to the heating trace.
In certain implementations, the thermally cured sealing material is in physical contact with at least a portion of the electrical heater trace. The electrical heater trace may be positioned near an edge of the second component and configured to be substantially uniformly heated when the electrical signal is applied to it, or to be non-uniformly heated when the electrical signal is applied to it. In certain implementations, the first component may further include a channel corresponding to at least one edge of the second component and configured to receive the sealing material. In accordance with certain exemplary implementations of the present invention, the apparatus is a print cartridge, in which the first component includes a pen body and the second component includes a flexible strip.
In accordance with still other exemplary implementations of the present invention, a method is also provided for providing a seal between at least two components using a thermally cured sealing material. Here, for example, the method includes selectively applying an electrical signal to a heating element on a first component, applying a sealing material between at least a portion of the first component and at least a portion of a second component, and at least partially thermally curing the sealing material using thermal energy generated by the application of the electrical signal to the heating element. Here, the heating element may include a heater trace that is produces a substantially uniform amount of thermal energy along the heater trace or a non-uniform amount of thermal energy along the heater trace. The selective application of the electrical signal to the heating element may be done prior to applying the sealing material, while applying the sealing material, and/or after applying the sealing material. The sealing material may, for example, include a sealant, an adhesive, glue, or other like substance.